1. Field of the Invention
The present invention relates to a photoacoustic measurement device, and more particularly, to a photoacoustic image generating device that generates a photoacoustic image on the basis of photoacoustic waves generated due to the emission of light after light is emitted to a subject. Further, the invention relates to a puncture needle that is used for the photoacoustic image generating device.
2. Description of the Related Art
An ultrasonic inspection method is known as one kind of image inspecting method that can inspect the internal state of a living body in a non-invasive manner. An ultrasonic probe, which can transmit and receive ultrasonic waves, is used for ultrasonic inspection. When ultrasonic waves are transmitted to a subject (living body) from the ultrasonic probe, the ultrasonic waves travel in the living body and are reflected by a tissue interface. When a distance is calculated on the basis of a time until the reflected ultrasonic waves return to the ultrasonic probe after the reflected ultrasonic waves are received by the ultrasonic probe, an image of the inner state of the living body can be made.
Further, photoacoustic imaging, which makes an image of the inside of a living body by using a photoacoustic effect, is known. In general, the inside of the living body is irradiated with pulsed laser light, such as laser pulses, in photoacoustic imaging. In the living body, biological tissue absorbs the energy of the pulsed laser light and ultrasonic waves (photoacoustic waves) are generated due to adiabatic expansion caused by the energy. When the photoacoustic waves are detected by an ultrasonic probe or the like and a photoacoustic image is formed on the basis of detection signals, the inside of the living body can be made visible on the basis of the photoacoustic waves.
Here, a combination of biological information imaging using photoacoustic waves and treatment using a puncture needle is mentioned in JP2009-31262A. In JP2009-31262A, a photoacoustic image is generated and is observed to find an affected part, such as a tumor, a portion that is suspected as an affected part, and the like. In order to more closely inspect such a portion or in order to perform injection or the like on an affected part, cells are taken or injection is performed on an affected part by using an injection needle, or a puncture needle such as a cytodiagnosis needle. In JP2009-31262A, it is possible to insert a needle to an affected part while observing the affected part, by using a photoacoustic image.